Hardener for hydraulic binder, hardener slurry, two-component hardenable composition, hydraulic composition slurry for layered manufacturing and manufacturing method thereof, manufacturing method of laminate, and hardened product

Abstract

To provide a curing agent for a hydraulic binder, capable of obtaining a hydraulic composition having sufficient mixability, laminability, rapid curability, and strength development properties, when mixed with a main material containing the hydraulic binder.SOLUTION: A curing agent for a hydraulic binder comprises an alum and a basic aluminum salt, wherein the basic aluminum salt is a basic salt containing an aluminum ion and a 2-6C hydroxy acid ion.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a hardener for hydraulic binders, a hardener slurry, a two-component hardenable composition, a hydraulic composition slurry for layered manufacturing and a method for producing the same, a method for producing a laminate, and a hardened cement product. [Background technology]

[0002] Additive manufacturing is a method of building a structure by repeatedly processing materials such as resin, metal, and ceramic in two dimensions based on three-dimensional data of the desired object. Among these methods, the material extrusion method is a method in which the building material is selectively extruded directly through an opening such as a nozzle and stacked, and in recent years, active research has been conducted into extrusion-based additive manufacturing technology using cement or clay mineral slurry.

[0003] When performing additive manufacturing using the material extrusion method, the performance required of the additive manufacturing material (curable composition) includes, for example, the ease with which the material can be delivered (hereinafter referred to as "delivery ability") and the ability of the material to not deform under its own weight after coming out of the nozzle but before hardening (hereinafter referred to as "laminability"). Generally, there is a trade-off between the delivery ability and the lamination ability of a material; for example, a material with high fluidity and good delivery ability is likely to be unable to maintain its laminated shape and to collapse.

[0004] To resolve the trade-off between liquid flowability and buildability, materials are typically designed to have high thixotropy, which means that viscosity is time- and shear-rate-dependent. Highly thixotropic materials offer high liquid flowability because their viscosity decreases due to shear stress applied by the pump or flow path during delivery, and their viscosity and yield value recover after discharge, allowing buildability to be achieved. For example, Patent Documents 1 and 2 disclose modeling cement compositions based on the concept of highly thixotropic materials and additive manufacturing methods using them. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-185645 [Patent Document 2] Japanese Patent Application Publication No. 2018-140906 Summary of the Invention [Problem to be solved by the invention]

[0006] However, one-component curable compositions begin curing the moment they are mixed with water, which requires complicated time management and makes it difficult to achieve both usable time and lamination properties. Even two-component curable compositions can have poor mixability due to the formation of flocs when the main component containing a hydraulic binder is mixed with the curing agent. Furthermore, conventional curable compositions still have insufficient lamination properties, and the strength of the resulting hardened cement body is often insufficient.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a hardener for a hydraulic binder that can obtain a cement composition having sufficient mixability, layerability, rapid hardening property, and strength development property when mixed with a main material containing a hydraulic binder. Another aim of the present invention is to provide a hardener slurry, a two-component hardenable composition, a hydraulic composition slurry for additive manufacturing and a method for producing the same, a method for producing a laminate, and a hardened product, using such a hardener for a hydraulic binder. [Means for solving the problem]

[0008] As a result of intensive research conducted by the present inventors to solve the above-mentioned problems, they discovered that mixing a main component containing a hydraulic binder with a curing agent containing alum and a basic aluminum salt is effective for producing a two-component curable composition that has a good balance of mixability, layerability, rapid curing properties, and strength development properties, and thus completed the present invention. That is, the curing agent for hydraulic binders of the present invention contains alum and a basic aluminum salt, and the basic aluminum salt is a basic salt containing an aluminum ion and a hydroxy acid ion having 2 to 6 carbon atoms.

[0009] The average particle size of the alum is preferably 0.05 to 1.0 mm.

[0010] The basic aluminum salt is preferably basic aluminum lactate.

[0011] A hardening agent for hydraulic binders for hardening a base slurry containing a hydraulic binder, a retarder and water.

[0012] It is preferable that the main material slurry contains aggregate.

[0013] It is preferable that the hardening agent for hydraulic binder contains at least one of siliceous powder and aggregate.

[0014] The hardener slurry of the present invention contains a hardener for hydraulic binders and water.

[0015] The two-component curable composition of the present invention comprises a main material and a curing agent in a separated state, the main material containing a hydraulic binder and a retarder, the curing agent containing alum and a basic aluminum salt, and the basic aluminum salt being a basic salt containing an aluminum ion and a hydroxy acid ion having 2 to 6 carbon atoms.

[0016] The hydraulic composition slurry for additive manufacturing of the present invention contains a hydraulic binder, a retarder, alum, a basic aluminum salt, and water, and the basic aluminum salt is a basic salt containing an aluminum ion and a hydroxy acid ion having 2 to 6 carbon atoms.

[0017] The hydraulic composition slurry for layered manufacturing preferably further contains at least one of a siliceous powder and an aggregate.

[0018] The method for producing a hydraulic composition slurry for layered manufacturing of the present invention includes mixing a main material slurry containing a hydraulic binder, a retarder, and water with the above-mentioned hardener slurry.

[0019] The method for producing a laminate of the present invention includes manufacturing a laminate of the hydraulic composition slurry for layered manufacturing.

[0020] The cured product of the present invention is a cured product of a laminate. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a hydraulic binder curing agent that can obtain a hydraulic composition having sufficient mixability, layerability, rapid hardening property, and strength development property when mixed with a main material containing a hydraulic binder. Furthermore, according to the present invention, it is possible to provide a hardener slurry, a two-component hardenable composition, a hydraulic composition slurry for additive manufacturing and a method for producing the same, a method for producing a laminate, and a hardened product, which use such a hydraulic binder curing agent. DETAILED DESCRIPTION OF THE INVENTION

[0022] <Curing agent for hydraulic binder> A hydraulic binder curing agent according to one embodiment of the present invention contains alum and a basic aluminum salt, and the basic aluminum salt is a basic salt containing an aluminum ion and a hydroxy acid ion having 2 to 6 carbon atoms. When mixed with a base material containing a hydraulic binder, this hydraulic binder curing agent can produce a hydraulic composition with sufficient mixability, layerability, rapid hardening properties, and strength development. Furthermore, the curable composition obtained by mixing the hydraulic binder curing agent of this embodiment with the base material also has excellent liquid transport properties. The hydraulic binder curing agent is in a state without water added (e.g., premix powder), and is used in a state such as a slurry by adding water when used.

[0023] (Alum) In this specification, alum refers to a double salt of a sulfate of a monovalent cation and a sulfate of a trivalent metal ion. The alum is not particularly limited, but examples thereof include potassium alum, ammonium alum, sodium alum, iron alum, chromium alum, and their anhydrides (burnt alum). Only one of these alums may be used, or multiple types may be mixed and used. Potassium alum is preferred from the standpoints of availability and price, as well as when preparing a curing agent slurry containing water.

[0024] The average particle size of the alum may be 0.05 to 1.0 mm, preferably 0.1 to 0.9 mm, more preferably 0.2 to 0.8 mm, and even more preferably 0.3 to 0.7 mm. When the particle size of the alum is within the above range, aggregation does not occur when the alum is mixed with the main material slurry, and mixability can be improved.

[0025] The average particle size of alum is determined from the volume-based frequency distribution measured using a laser diffraction / scattering particle size distribution analyzer, such as the "SALD-2200" manufactured by Shimadzu Corporation, under dry conditions. A specific procedure for calculating the average particle size of alum may be as follows: From the relationship between the volume-based frequency and the particle size obtained by measurement using a laser diffraction / scattering particle size distribution analyzer, a weighted average value is calculated for the logarithmic value of the particle size, with the volume-based frequency for that particle size as the weight.

[0026] The content of alum is preferably 2 to 20 mass %, more preferably 5 to 15 mass %, and even more preferably 7 to 12 mass %, relative to the total amount of hydraulic binder in the main material slurry to be mixed. By having the alum content within the above range, suitable rapid hardening properties and strength development can be obtained.

[0027] The content of alum in the hydraulic binder curing agent is preferably 3 to 90 mass%, more preferably 5 to 70 mass%, even more preferably 7 to 50 mass%, and particularly preferably 7 to 20 mass%, based on the total amount of the hydraulic binder curing agent. The content of alum in the hydraulic binder curing agent may be 65 to 98 mass%, 70 to 95 mass%, or 75 to 90 mass%, based on the total amount of alum and basic aluminum salt. By having the alum content within the above range, suitable rapid hardening properties and strength development can be obtained when mixed with the main material slurry.

[0028] (basic aluminum salt) The basic aluminum salt contained in the curing agent for hydraulic binders of this embodiment is a basic salt containing aluminum ions and hydroxy acid ions having 2 to 6 carbon atoms. Here, the basic salt is a basic salt containing hydroxide ions (OH - In other words, a basic aluminum salt is a salt of aluminum and a hydroxy acid in which part of the anion has been replaced with a hydroxide ion. A basic aluminum salt has the general formula: Al(OH) 3-x Y b where x and b are selected so that the basic aluminum salt as a whole is electrically neutral. By using a basic aluminum salt, the formation of flocs can be suppressed, thereby improving the mixability in particular.

[0029] The number of carbon atoms contained in the hydroxy acid ion contained in the basic aluminum salt is preferably 2 to 4, more preferably 2 or 3, and even more preferably 3.

[0030] Examples of basic aluminum salts include basic aluminum lactate, basic aluminum hydroxyacetate, basic aluminum citrate, and basic aluminum tartrate, with basic aluminum lactate being preferred. These may be hydrates. Only one basic aluminum salt may be used, or two or more basic aluminum salts may be used in combination.

[0031] Basic aluminum lactate has the general formula Al(OH) 3-x (Lac.acid) x (0 < x < 3), and those with a molar ratio of Al2O3 / lactic acid of 0.3 to 2.0 are preferred. Here, Lac.acid is a lactate ion. Basic aluminum lactate may be a hydrate. Examples of commercially available basic aluminum lactate include "Taxeram M160-P" (manufactured by Takaki Chemical Co., Ltd.), etc., and these can be used.

[0032] The content of the basic aluminum salt is preferably 0.5 to 3.0% by mass, more preferably 0.7 to 2.8% by mass, and still more preferably 1.0 to 2.5% by mass, based on the total amount of the hydraulic binder in the main material slurry to be mixed. When the content of the basic aluminum salt is within this range, more suitable lamination properties and rapid hardening properties can be obtained when mixed with the main material slurry, and abnormal setting or a decrease in strength development tendency can be suppressed.

[0033] The content of the basic aluminum salt in the hardener for hydraulic binder is preferably 1.0 to 20% by mass, more preferably 1.5 to 17% by mass, still more preferably 2.0 to 15% by mass, and particularly preferably 2.5 to 5% by mass, based on the total amount of the hardener for hydraulic binder. Also, the content of the basic aluminum salt may be 10 to 35% by mass, 12 to 30% by mass, or 15 to 25% by mass based on the total amount of alum and the basic aluminum salt. When the content of the basic aluminum salt is within this range, more suitable lamination properties and rapid hardening properties can be obtained when mixed with the main material slurry, and abnormal setting or a decrease in strength development tendency can be suppressed.

[0034] In addition to alum and basic aluminum lactate, the hardener for hydraulic binder may contain siliceous powder, aggregate, defoaming agent, thickener, fluidizing agent, fiber, etc. It is preferable that the hardener for hydraulic binder contains at least one of siliceous powder and aggregate.

[0035] (Siliceous powder) The type of siliceous powder is not particularly limited, but any powder containing silica may be used, such as silica fume (e.g., as specified in JISA6207:2016 "Silica fume for concrete"), fly ash (e.g., as specified in JISA6201:2015 "Fly ash for concrete"), silica powder, kaolin, metakaolin, etc. By including a siliceous powder in the hardener for hydraulic binder according to this embodiment, the liquid transportability, lamination properties, and strength development properties of the hardener slurry and the hydraulic composition slurry for additive manufacturing can be further improved.

[0036] The specific surface area (Blaine value or BET specific surface area) of the siliceous powder is preferably 2000 cm 2 / g or more, more preferably 3000 cm 2 / g or more.

[0037] When the hydraulic binder curing agent contains a siliceous powder, the content of the siliceous powder is preferably 5 to 100 mass %, more preferably 7 to 70 mass %, and even more preferably 10 to 50 mass %, relative to the total amount of the hydraulic binder in the main slurry.

[0038] When the hydraulic binder curing agent contains a siliceous powder, the content of the siliceous powder in the hydraulic binder curing agent is preferably 5 to 60 mass %, more preferably 10 to 55 mass %, and even more preferably 15 to 50 mass %, based on the total amount of the hydraulic binder curing agent.

[0039] (aggregate) The aggregate is preferably silica sand used for concrete aggregates as specified in JISA5308:2019, etc., or building materials. The particle size of the aggregate is preferably less than 2000 μm, more preferably less than 1180 μm, from the viewpoint of the pumpability of the hardener slurry and the hydraulic composition slurry for additive manufacturing. The particle size of the sand can be measured using several sieves with different mesh sizes as specified in JIS Z8801-1:2019. When the hydraulic binder hardener contains aggregate, the content of the aggregate in the hydraulic binder hardener is, for example, 10 to 80 mass%, preferably 20 to 70 mass%, and more preferably 30 to 60 mass%, based on the total mass of the hydraulic binder in the main material and the aggregate in the main material.

[0040] When the hardener for hydraulic binders contains aggregate, the content of the aggregate in the hardener for hydraulic binders is 10 to 90 mass %, preferably 15 to 80 mass %, and more preferably 20 to 70 mass %, based on the total amount of the hardener for hydraulic binders.

[0041] (Antifoaming agent) When the hydraulic binder curing agent contains an antifoaming agent, the strength development of the hydraulic composition slurry for layered manufacturing can be improved. Known defoaming agents can be used. Specific examples of defoaming agents include synthetic substances such as mineral oil-based, silicone-based, alcohol-based, and polyether-based agents, or natural substances derived from plants. From the viewpoint of dispersibility and durability, polyether-based and mineral oil-based defoaming agents are preferred. One type of defoaming agent can be used, or two or more types of defoaming agents can be used in combination.

[0042] The content of the antifoaming agent is preferably 0.02 to 1.0 mass %, more preferably 0.05 to 0.7 mass %, and even more preferably 0.1 to 0.5 mass %, based on the total amount of the hydraulic binder in the main slurry.

[0043] The content of the antifoaming agent in the hydraulic binder curing agent is preferably 0.05 to 3.0 mass %, more preferably 0.1 to 2 mass %, and even more preferably 0.12 to 1 mass part, based on the total amount of the hydraulic binder curing agent.

[0044] The hardener for hydraulic binders may be a premixed powder obtained by mixing powders together, or may be a hardener slurry containing water. The water contained in the hardener slurry is not particularly limited, and may be, for example, tap water, distilled water, deionized water, etc. The water content in the hardener slurry may be 5 to 70% by mass, or 10 to 50% by mass, based on the total amount of the hardener slurry.

[0045] <Main material> The main material is not particularly limited, and any composition containing a hydraulic binder can be used without particular limitation. The main material may be a premixed powder in which powders are mixed together, or a main material slurry containing water.

[0046] The base slurry may include a hydraulic binder, a retarder, and water.

[0047] (Hydraulic binder) In this specification, the hydraulic binder refers to a material that contains cement and exhibits hydraulic properties, and may contain an admixture. Examples of cement include various Portland cements such as ordinary Portland cement, early-strength Portland cement, extra-early-strength Portland cement, moderate-heat Portland cement, low-heat Portland cement, and sulfate-resistant Portland cement, as well as various blended cements such as blast-furnace cement and fly ash cement. Only one of these cements may be used, or multiple types may be mixed and used. Among these, from the viewpoint of improving the hardening characteristics of the hydraulic composition slurry for additive manufacturing, it is more preferable to use at least one Portland cement selected from the group consisting of ordinary Portland cement, early-strength Portland cement, and extra-early-strength Portland cement.

[0048] The hydraulic binder may further contain an admixture. Examples of admixtures include ground granulated blast furnace slag (e.g., those conforming to JISA6206:2013 "Ground granulated blast furnace slag for concrete"), ground limestone, silica fume (e.g., those specified in JISA6207:2016 "Silica fume for concrete"), fly ash (e.g., those specified in JISA6201:2015 "Fly ash for concrete"), kaolin, metakaolin, silica powder, and expansive additives. Among these, ground granulated blast furnace slag is preferred from the viewpoint of the pumpability and fluidity retention time (use life) of the main material slurry and the hydraulic composition slurry for additive manufacturing. When the admixture is contained, the content thereof is, for example, 1 to 99 mass %, preferably 10 to 90 mass %, and more preferably 30 to 70 mass %, relative to the total amount of hydraulic binder in the main material. By ensuring that the content of the admixture is within the above range, it is possible to achieve suitable pumpability and flow retention time for the main material slurry.

[0049] The ground granulated blast furnace slag preferably conforms to JISA6206:2013 "ground granulated blast furnace slag for concrete." The Blaine specific surface area of ​​the blast furnace slag is preferably 2500 to 10000 cm 2 / g, more preferably 3000 to 9000 cm 2 / g, more preferably 4000 to 8000 cm 2 / g.

[0050] (retardant) The retarder is not particularly limited, and examples thereof include hydroxycarboxylic acids, sugars, inorganic retarders, etc., with hydroxycarboxylic acids being preferred.

[0051] The hydroxycarboxylic acids include hydroxycarboxylic acids and their salts, such as gluconic acid, tartaric acid, citric acid, malic acid, succinic acid, and heptonic acid.

[0052] Examples of the salts of hydroxycarboxylic acids include alkali metal salts (sodium salt, potassium salt, etc.) and alkaline earth metal salts (calcium salt, magnesium salt, etc.), of which sodium salts are more preferred. Sodium gluconate is particularly preferred in terms of its setting retardation effect, availability, and cost. One type of hydroxycarboxylic acid can be used, or two or more types of components can be used in combination.

[0053] When the main material contains a retarder, the content of the retarder is preferably 0.05 to 1.5 mass %, more preferably 0.1 to 1.0 mass %, and even more preferably 0.2 to 0.8 mass %, relative to the total amount of hydraulic binder in the main material. By setting the content of the retarder within the above range, a suitable fluidity retention time (workable life) can be obtained.

[0054] (water) The water contained in the main slurry is not particularly limited and may be, for example, tap water, distilled water, deionized water, etc. The content of water in the main slurry is preferably 20 to 100 mass %, more preferably 25 to 90 mass %, and even more preferably 30 to 80 mass %, based on the total amount of hydraulic binder.

[0055] The main material may contain, in addition to the hydraulic binder, retarder and water, aggregate, thickener, water-reducing agent, antifoaming agent, fiber, etc. It is preferable that the main material slurry contains aggregate.

[0056] (aggregate) The aggregate in the main material is preferably concrete aggregate as specified in JISA5308:2019 or silica sand used in building materials. The particle size of the aggregate is preferably less than 2000 μm, more preferably less than 1180 μm, from the viewpoint of the pumpability of the main material slurry and the cement slurry for additive manufacturing. The particle size of the aggregate can be measured using several sieves with different mesh sizes as specified in JIS Z8801-1:2019. When the main material contains aggregate, the content of the aggregate in the main material is, for example, 1 to 80 mass%, preferably 20 to 70 mass%, and more preferably 30 to 70 mass%, based on the total amount of the hydraulic binder and aggregate.

[0057] (water reducing agent) The main material preferably further contains a water-reducing agent within a range that does not impair the effects of the present invention. By including a water-reducing agent, it is possible to realize a main material slurry with improved liquid transportability. Examples of the water-reducing agent that can be preferably used include polycarboxylic acid-based water-reducing agents. Specific examples of polycarboxylic acid-based water-reducing agents include polyether-polycarboxylic acid-based water-reducing agents and modified polycarboxylic acid-based water-reducing agents. The base material slurry according to the present invention can use these water-reducing agents alone or in combination of two or more components. The content of the water-reducing agent is preferably 0.05 to 1.0 mass %, more preferably 0.1 to 0.7 mass %, and even more preferably 0.2 to 0.5 mass %, relative to the total amount of hydraulic binder in the main material. By setting the content of the water-reducing agent within the above range, the liquid transportability can be further improved.

[0058] (thickener) The main material may contain a thickener to the extent that the effects of the present invention are not impaired. Specific examples of the thickener include organic thickeners such as cellulose-based thickeners, starch-based thickeners, guar gum-based thickeners, and vinyl-based thickeners, as well as inorganic thickeners such as bentonite, kaolinite, and talc. These may be used alone or in combination of two or more components. The content of the thickener is preferably 0.01 to 1.0 mass %, more preferably 0.03 to 0.8 mass %, and even more preferably 0.05 to 0.5 mass %, based on the total amount of hydraulic binder in the main slurry.

[0059] (Fluidity of main material slurry (liquid transfer ability)) The fluidity of the main material slurry can be evaluated by the flow test described in "JIS R 5021:2015 Physical Testing Methods for Cement." The flow value after 15 drops is preferably 140 mm or more, more preferably 150 mm or more, and even more preferably 170 mm or more. The flow value of the main material slurry can be adjusted by, for example, the ratio of water to hydraulic binder, the ratio of aggregate, the content of superplasticizer, etc.

[0060] The two-component curable composition of this embodiment may comprise the main material and the hydraulic binder curing agent (curing agent) in a separate state. The main material in the two-component curable composition may be a premixed powder or a main material slurry containing water. The curing agent in the two-component curable composition may be a premixed powder or a curing agent slurry containing water.

[0061] The two-component curable composition of the present embodiment is used by contacting a base material slurry and a curing agent slurry. Therefore, the two are kept separate so as not to come into contact with each other until use. For example, the base material and the curing agent may be kept packaged in separate containers, bags, etc.

[0062] <Hydraulic composition slurry for additive manufacturing> The hydraulic composition slurry for additive manufacturing of this embodiment is a mixture of the above-mentioned main material slurry and hardener slurry. That is, the hydraulic composition slurry for additive manufacturing contains a hydraulic binder, a retarder, alum, a basic aluminum salt, and water, and the basic aluminum salt is a basic salt containing aluminum ions and hydroxy acid ions having 2 to 6 carbon atoms. The hydraulic composition slurry for additive manufacturing may be a hydraulic mortar composition.

[0063] The method for producing the hydraulic composition slurry for additive manufacturing of this embodiment is not particularly limited, but an example thereof includes a method including preparing a main material slurry and a hardener slurry and mixing them together. The method for mixing the main material slurry and the hardener slurry is not particularly limited, but for example, an in-line mixer such as a static mixer or a dynamic mixer, a Hobart mixer, a concrete mixer, a mortar mixer, or the like can be used.

[0064] The hydraulic composition slurry for additive manufacturing of this embodiment can be used, for example, to produce a three-dimensional object. The three-dimensional object may be produced, for example, by a 3D printer. The hydraulic composition slurry for additive manufacturing may be ejected from a nozzle or the like to form a layer, or a laminate may be produced by repeatedly forming layers on the formed layer. The hardened product of this embodiment may be produced by hardening the hydraulic composition slurry for additive manufacturing or by hardening the laminate. [Example]

[0065] The present invention will be described in more detail below based on specific examples, but the present invention is not limited to the following examples and can be implemented with appropriate modifications within the scope that does not change the gist of the present invention.

[0066] <Materials used> Cement (C): High-early-strength Portland cement (manufactured by Ube Mitsubishi Cement Co., Ltd.) Admixture (BFS): Blast furnace slag powder "Powerment" (manufactured by Ube Mitsubishi Cement Co., Ltd.) Blaine specific surface area 4670 cm 2 / g Water reducing agent (SP): Polycarboxylic acid-based high-performance water reducing agent "Mighty 21P" (Kao Corporation) Thickener (MC): Water-soluble methylcellulose thickener "Marporose 90MP-300T" (Matsumoto Oil & Fat Co., Ltd.) Retarder (GNa): Sodium gluconate (reagent) Fine aggregate 1 (S1): Kashima silica sand No. 6 (Takano Shoji Co., Ltd.) Fine aggregate 2 (S2): No. N70 (manufactured by Nichihyogyo Co., Ltd.) Water (W): Tap water Accelerator 1 (Alm1): Commercially available potassium alum crushed and classified (average particle size: 0.62 mm) Accelerator 2 (Alm2): Commercially available potassium alum crushed and classified (average particle size: 0.46 mm) Accelerator 3 (Alm3): Commercially available potassium alum crushed and classified (average particle size: 0.12 mm) Accelerator 4 (AF): Commercially available aluminum sulfate-based liquid accelerator (containing 50% aluminum sulfate) Basic aluminum lactate (AlLac): "Taxeram M-160P" (manufactured by Taki Chemical Co., Ltd.) Silica powder (SF): Silica fume "EFACO" (Tomoe Engineering Co., Ltd.) BET specific surface area: 16.9 m 2 / g Defoaming agent (DF): "Adekanate B115F" (ADEKA Corporation)

[0067] <Main material slurry production and stability> The powdered raw materials in Table 1 were dry mixed in advance to prepare a premix powder. The specified amount of water was added to this and mixed at low speed in a Hobart mixer for 30 seconds, after which the mixing was stopped for 30 seconds and any powder or paste adhering to the sides and bottom of the container was scraped off. After the pause, the mixture was mixed at medium speed for 90 seconds and left to stand for 30 minutes. After leaving to stand, the mixture was mixed again at medium speed for 90 seconds to prepare the main material slurry. The stability of the produced main slurry was confirmed by a flow test described in "JISR5201:2015 Physical Testing Methods for Cement." Every other day, the slurry was mixed at medium speed for 90 seconds using a Hobart mixer, and the flow was measured after 15 drops. The flow value immediately after production was 198 mm. After a further 8 days, the flow value was 182 mm.

[0068] [Table 1]

[0069] <Production and stability of hardener slurry> The powdered raw materials in Table 2 were mixed in advance to prepare a premix powder. Water was added to this and the mixture was kneaded at low speed in a Hobart mixer for 30 seconds, after which the mixing was stopped for 30 seconds and any powder or paste adhering to the sides and bottom of the container was scraped off. After the pause, the mixture was kneaded at high speed for 120 seconds to prepare a hardener slurry. The stability of the hardener slurry was confirmed by pH and flow tests. Every other day, the slurry was mixed at medium speed for 90 seconds using a Hobart mixer, and then the pH and mortar flow at 15 strokes were measured. Immediately after production, the pH was 3.2 and the mortar flow at 15 strokes was 190 mm. Eight days later, the pH was 3.7 and the mortar flow at 15 strokes was 192 mm. This shows that the hardener slurry, like the base slurry, maintained its suitable fluidity even after more than a week had passed.

[0070] [Table 2]

[0071] <Evaluation of Mixability> (Evaluation 1: Mixing of two liquids using a cartridge) A hardener slurry was prepared having the composition shown in Table 3. In the following Tables 3 and 4, the blending amount is the amount relative to 100% by mass of the hydraulic binder as the main component. Using a two-component cartridge system "DM400 manual gun" (manufactured by MIXPAC) and a static mixer, the main material slurry and hardener slurry were mixed while being fed. The main material slurry in Table 1 and the hardener slurry in Table 3 were separately filled into separate dedicated cartridges "CD400" and set into the manual gun, and a static mixer (model 262-616-01) was connected to the tip. The trigger of the manual gun was pulled to simultaneously discharge and feed each slurry, and those that reached the tip of the static mixer were marked with an "O", and those that caused blockage of the static mixer midway were marked with an "X".

[0072] (Evaluation 2: Current value when mixing with a Hobart mixer) The base material slurry prepared according to the formulation in Table 1 was placed in the Hobart mixer's container, followed by the hardener slurry prepared according to the formulation in Table 3. The mixture was mixed at medium speed for 60 seconds to produce a hydraulic composition slurry for additive manufacturing. A clamp logger "ZN-CTC11" (Omron Corporation) was connected to the Hobart mixer's power cord to measure the current and quantitatively evaluate the mixing performance upon addition of the hardener slurry. The maximum value (a) and the converged asymptotic value (b) were extracted from the current measurement data, and the a / b ratio was calculated. The smaller the a / b ratio, the more stable the Hobart mixer's operation and the lower the load during mixing, i.e., the better the mixing performance.

[0073] [Table 3]

[0074] <Production of hydraulic composition slurry for additive manufacturing> The main material slurry produced according to the formulation in Table 1 was placed in the container of a Hobart mixer, and the hardener slurries produced according to the formulation in Table 4 were then added and mixed at medium speed for 60 seconds to produce hydraulic composition slurries for additive manufacturing. These hydraulic composition slurries for additive manufacturing were evaluated for the mixability described above, as well as the lamination property, rapid hardening property, and strength development described below.

[0075] (Evaluation of lamination: rubber hardness measurement) The mixed cement slurry for additive manufacturing was filled into a φ125mm x H25mm stainless steel dish, and the surface was smoothed with a scraper. The surface was covered with plastic wrap, and an Asker Rubber Hardness Tester Type F (manufactured by Kobunshi Keiki Co., Ltd.) was slowly placed on the dish and the scale was read. As shown in non-patent literature (see Maebori Shinpei et al., "Cement and Concrete," Cement Association, October 2020, No. 884, pp. 9-15), there is a certain relationship between the reading of the rubber hardness tester in a static state and the buildable height, so rubber hardness can be used as an indicator of buildability.

[0076] (Evaluation of rapid hardening: Measurement of initial hardening time) The initial release time of the cement slurry used in additive manufacturing was measured using a Vicat needle device in accordance with "JISR5021:2015 Physical Test Methods for Cement." If the material reaches the initial release time, the material will not sag or undergo any other deformation, and its self-supporting properties will be sufficient.

[0077] <Evaluation of strength development: Compression strength test> In accordance with "JISR5021:2015 Physical Testing Methods for Cement," 40mm x 40mm x 160mm specimens were prepared and subjected to compressive strength tests at 1 and 7 days of age. The formwork was removed immediately before measuring the strength at 1 day of age, after which the specimens were allowed to cure in air at 20°C and 50% RH.

[0078] [Table 4]

[0079] <Result> All of Examples 2-1 to 2-8 were excellent in mixability, lamination property, rapid curing property, and strength development property. In Comparative Examples 2-1 and 2-2, when a commercially available aluminum sulfate-based quick-setting admixture AF was used at 5.3 to 7.0% B, flocs formed in the mixer, increasing the current value of the mixer, resulting in poor mixability. When the amount of aluminum sulfate-based quick-setting admixture was further reduced (Comparative Example 2-3), mixability improved, but subsequent lamination, rapid hardening, and strength development all deteriorated. In Comparative Example 2-4, when the hardener contained alum but did not contain basic aluminum lactate, the laminateability was poor.In Comparative Example 2-5, when the hardener did not contain a sulfuric acid-based quick-setting agent and only basic aluminum lactate was added, the strength development was poor.

Claims

1. alum and a basic aluminum salt, The hardening agent for hydraulic binders, wherein the basic aluminum salt is a basic salt containing an aluminum ion and a hydroxy acid ion having 2 to 6 carbon atoms.

2. 2. The hardening agent for hydraulic binders according to claim 1, wherein the average particle size of the alum is 0.05 to 1.0 mm.

3. 3. The hardening agent for hydraulic binders according to claim 1, wherein the basic aluminum salt is basic aluminum lactate.

4. The hardening agent for hydraulic binders according to any one of claims 1 to 3, for hardening a base slurry containing a hydraulic binder, a retarder and water.

5. The hardening agent for hydraulic binders according to claim 4 , wherein the base slurry contains aggregate.

6. The hardening agent for hydraulic binders according to any one of claims 1 to 5, comprising at least one of a siliceous powder and an aggregate.

7. A hardener slurry comprising the hardener for hydraulic binders according to any one of claims 1 to 6 and water.

8. The main material and hardener are separated, The main material includes a hydraulic binder and a retarder, the hardening agent comprises alum and a basic aluminum salt; The two-component curable composition, wherein the basic aluminum salt is a basic salt containing an aluminum ion and a hydroxy acid ion having 2 to 6 carbon atoms.

9. It comprises a hydraulic binder, a retarder, alum, a basic aluminum salt and water, The hydraulic composition slurry for additive manufacturing, wherein the basic aluminum salt is a basic salt containing an aluminum ion and a hydroxy acid ion having 2 to 6 carbon atoms.

10. The hydraulic composition slurry for layered manufacturing according to claim 9, further comprising at least one of a siliceous powder and an aggregate.

11. A method for producing a hydraulic composition slurry for additive manufacturing, comprising mixing a main material slurry containing a hydraulic binder, a retarder, and water with the hardener slurry according to claim 7.

12. A method for manufacturing a laminate, comprising manufacturing a laminate using the hydraulic composition slurry for layered manufacturing according to claim 9 or 10.

13. A hardened body which is a hardened product of the hydraulic composition slurry for additive manufacturing described in claim 9 or 10.

14. The main material and the hardener of the two-component hardenable composition described in claim 8 are a main material slurry and a hardener slurry, respectively, containing water, and the hardened body is obtained by hardening a hydraulic composition slurry for additive manufacturing, which is a mixture of the main material slurry and the hardener slurry.

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